U.S. markets were mainly lower despite data that showed that U.S. manufacturing grew in August at the strongest pace in more than three years.

The Dow Jones industrials dropped 30.89 points to 17,067.56 as the Institute for Supply Management’s index for August came in at 59, up from 57.1 in July.

“We’ve had some early indications that things were trending in the right direction for the manufacturing sector, but that number is certainly better than expected,” said Jean-Francois Dion, portfolio adviser, RBC Wealth Management.

The Nasdaq was up 17.92 points at 4,598.19 while the S&P 500 index lost 1.09 points to 2,002.28.

The news was also positive from Canada as the RBC Canadian manufacturing purchasing managers’ index for August showed the group gained momentum in August with overall business conditions improving at the fastest past since last November. The index registered 54.8 in August, up from 54.3 in July.

But other data showed China’s official purchasing managers’ index dropped to 51.1 in August, while the private sector measure fell to a 50.2 reading, both worse than expected results.

Traders were cautious ahead of the major economic event of the week. The U.S. government releases its employment report for August on Friday and economists are looking for another strong month of job creation in the neighbourhood of 220,000.

In other major economic events this week, Canadian jobs data also comes out on Friday and the Bank of Canada makes its scheduled announcement on interest rates on Wednesday.

The TSX gold sector dropped about three per cent as December bullion fell $22.40 to US$1,265 an ounce. Gold had found some support amid tensions between Russia and western countries over its involvement in fighting between rival factions in Ukraine. But the metal is being pressured at the same time by a rising U.S. dollar, the end of quantitative easing by the U.S. Federal Reserve expected this fall and the prospect of higher interest rates.

“The strength in the U.S. dollar has probably more than offset the rising geopolitical tensions,” Dion said.

“It’s still a very challenging environment for most gold companies. A lot of them have seen increases in their operating costs.”

The energy sector fell 1.85 per cent as the Chinese data and a higher U.S. dollar pushed October crude down $3.08 to US$92.88 a barrel. A higher U.S. dollar pressures commodities because a stronger greenback makes it more expensive for holders of other currencies to buy oil and metals which are dollar-denominated.

Pembina Pipeline Corp. will acquire a pipeline system and an interest in a Saskatchewan ethane extraction plant for US$650 million. The Vantage pipeline system originates in North Dakota and provides access to the North Dakota Bakken shale formation. Pembina shares rose $1.49 to $51.46.

Base metal stocks were also weak, down one per cent as December copper slipped one cent to US$3.15 a pound.

The market found support from the industrials group, up 1.25 per cent. But shares in Bombardier (TSX:BBD.B) slipped one cent to $3.65 after Goldman Sachs analyst Noah Paponak reiterated his sell rating on the stock and downgraded the share price from $3.20 to $3. He says it is “inevitable” there will be further delays in the company’s new CSeries airliner.